I don't know why but from all kdrama I've watched, this one (What's Wrong with Secretary Kim) makes me smile all day after watching their scenes. Like seriously ... And i think it's because of their chemistry and they immersed in the acting so much. Plus,they have the same family name in real life that makes me even more like them being together so much. Not sure how others agree on this ans I accept argument too because this is my opinion but strong chemistry while acting that went well is the last time was Descendant of the sun chemistry, then this one ???? Big thumbs up from me.